JPS62129737A - Delta p index measuring device for measuring oxidation rate - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

TECHNICAL FIELD The present invention relates to a method and apparatus for characterizing coal by its initial methane gas release rate under predetermined test conditions.

As part of its structure, coal contains pores and cracks ranging in size from a few angstroms to a few millimeters. The pores act as gas reservoirs, while the fissures act as transport arteries. The initial gas release rate from the coal is quite large and depends on the degree of cracking. If the gas continues to flow out through the very fine pores (0,01 m), the rate of release decreases and the evacuation follows the law of diffusion.

It has been shown that the friability of coal is related to the presence of numerous fractures on the order of 5 m thick. A useful crack indicator is the ΔP index, which indicates micro-fissrations in the coal and possibly
This is a measure of the initial release rate, depending on the size of the ostium and the distribution of deafness. Regarding the P index, see the paper by Ettinger et al.
Comparison of absorption of carbon dioxide and methane” (Fue145:35
1; 1966) and is used in France, Belgium and many other countries to obtain a measure of methane emission rate from coal and as an indirect means of classifying coal composition.

A study by the French CE rt CI-I Ar (CE) showed that the ΔP index of coal fragments of various sizes remains almost constant as long as the size of the coal particles is larger than the distance between the cracks. If the coal particle size is smaller than the above distance, the milling will develop more new surfaces than originally obtained, i.e. the particle size at which the ΔP index starts to increase will be As we correspond closer to the interval, the ΔP index increases.

The ΔP index is an experimental value based on tests performed according to standard procedures and using standard size equipment. As mentioned above, Δ
Measurement of the P-index provides a means of comparing the rate at which gas is released from different coals. The evacuation movement of gas from the coal particles is probably a two-step process, i.e., the gas is first released and diffused through the micropore structure and then flows out more rapidly through any cracks present. It occurs in the form of two steps.

The ΔP index provides very useful information including:

(a) Only prediction of fines during formal coal mining operations and during initial development.

(b) Measurement of the degree of coal oxidation before coal treatment and during coal storage.

(C) A measure of susceptibility to gas explosions in underground coal mines.

The ΔP measurement is carried out by saturating the coal sample with methane gas in a sample cup until essentially equilibrium absorption of methane gas onto the coal surface is achieved.

The sample tip volume is then determined by the additional, peri-drained multi-branch volume (add i -tional 1niti
ally evacuated manifold v
olume). Therefore, as the total system volume increases, the methane gas pressure immediately decreases. As a result of the decrease in pressure, there will be a corresponding decrease in pressure within the equilibrium mass of methane gas that remains absorbed on the coal surface. Thus, excess methane gas begins to be absorbed into the system volume determined by the time constant of the absorption/release mechanism. The resulting initial rate of pressure rise is the measurand used to characterize coal with ΔP index measurements.

The exact sample tip volume and manifold volume, like the initial gas pressure at constant pressure, are specific values of the standardized experiment. The ΔP index indicates the initial increase in gas pressure due to release during a predetermined interval of 50 seconds. The initial discharge pressure drop into the manifold volume is also used as a measurement parameter so that exact coal sample density is not required.

Prior Art Conventional ΔP index measurement systems utilize mercury manometers to measure pressure and manual valves to divert flow in the manifold. The pressure gauge is subject to transient effects and cannot be reliably read until about 10 seconds after the valve is opened. For this reason, determining whether or not the player is defeated becomes a very slow and time-consuming process.

OBJECTS OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks of the conventional HeP index measurement system, and it is an object of the present invention to provide a HeP index measurement system that is simple in construction and allows faster and more accurate results to be obtained. That is the purpose.

SUMMARY OF THE INVENTION In order to achieve the above objects, in one embodiment of the present invention, an apparatus for measuring the ΔP index in coal comprises: (a) a plurality of closed coal sample tips; and (b) a separate solenoid valve. a gas manifold flow path connected to each of the sample tips via a gas manifold, the manifold being connectable to a source of methane gas through solenoid valve means and also connected to a source of vacuum through solenoid valve means; (CC) further comprising a pressure transducer connected to said manifold and arranged to measure the absolute gas pressure in said manifold; (tl) processing means for actuating said valve; equipment provided.

The processing means comprises, for example, a microcomputer, and (1) introduces a vacuum to evacuate the manifold and one or more sample cups; (ii) introduces methane gas into the manifold; , saturate one or more coal sample tips therewith, close the sample tip valves and evacuate the manifold, and (iv) individually and selectively open each sample tip valve. As if to punish him, he responded one after another. Further, the processing means is characterized in that the pressure inside the manifold is measured and recorded at short intervals so as to indicate the increase in pressure within the manifold over time, and the ΔP index of each coal sample is obtained. do.

Furthermore, the present invention is also characterized by a step of measuring the HeP index in coal using the above-mentioned apparatus.

EXAMPLE The configuration of the present invention will be explained below with reference to the attached drawings.

In FIG. 1, the test apparatus of the present invention is provided with a main body unit IO having a cylindrical manifold 11. As shown in FIG.

A series of duralumin metal sample tips C are connected to the manifold 11. In this figure, eight sample chips are connected and designated by symbols c1 to C8. Each sample tip C has a microporous gauge snubber.
er) I 2 , connected to the manifold 11 via the solenoid valve V and the connector 13.

Solenoid valves Vl to V8 are valves corresponding to each sample tip C1 to 08.

One end of manifold II communicates with the atmosphere via solenoid valve 14, and the other end of manifold II is closed by solenoid valve 15. The valve 15 includes a proportional control valve 16 and a solenoid valve 1.
7. Connect to methane gas source 2I via ultra-high purity gas filter 18, flash arrester 19, and pressure regulator 20.

The manifold only has a branch 22 that connects to a vacuum source. This branch line 22 is connected to the solenoid valve 23 and the sample tip 2.
5. Cross line 26 and further connection to branch line 24 containing a manually controlled micrometer flow regulator 27. The main branch line 22 also has a solenoid valve 28.

The external extension of the branch line 22 includes a solenoid valve 29, a manual blow-off valve 30, an absorption filter 31, and a two-stage vacuum pump 3.
2 and mist filter 33.

The manifold 11 may also be, for example, a Teledyne-Taber model 22 l5 (Teledyne-Taber m5).
2215) or the like.

The output of the pressure transducer is, for example, Apple 20
Connected to the human power of a central processing unit such as a microcomputer, the output of the central processing unit is connected to different solenoid valves and to the proportional control valve 16. Just Pascal (
A microcomputer operated by a Pascal) computing system acts as a post providing the sequence, control and measurement functions necessary for the operation of the ΔPWiU.

Figure 2 shows details of the sample tip assembly;
From the same figure, the tip C is a cylindrical portion 40 having a threaded portion 41.
and a coupling nut 42 having an internal thread.

When nut 42 is screwed into threaded portion 41, it forces O-ring 43 against the side wall of sample tip 44, holding the tip in place.

A disk filter 45 and an O-
A ring 46 is provided. On this O-ring 46,
The plug member 49 and the snubber 47 are arranged on the bottom. This is connected to the upper connector member 48.

3 and 4 show a water-cooled aluminum cooling radiator (heat 5 ink) 50 that supports and cools the connector valves Vt to 8. This radiator 50 is provided with a main body 53 having an opening 54 for cooling water passing therethrough. Further, an upper horizontal flange portion 52,
A lower vertical flange portion 51 is provided. The upper flanone 52 is provided with an opening 56, and the lower flange portion 51 is provided with an opening 55. These openings 55 are for supporting V8 more than the side valves Vl. The radiator 50 has a valve Vl
This is used to prevent the heat generated from the valve when the valve (8) is closed to prevent it from affecting the experimental results.

A thermostatic proportional valve (not shown) maintains constant temperature water flow through the radiator.

To perform the test, a sample of coal is prepared and placed into one or more sample cups C1-08.

During operation, most valves are either fully open or fully closed under the control of the central processing unit. Proportional control valve 16 provides a variable orifice under control of the central processing unit. The proportional valve 27 also has a variable orifice, but once calibrated it remains unmodified.
The proportional valves in conjunction with tank 25 provide a means for smoothly and accurately controlling constant atmospheric gas pressure during the methane gas saturation cycle. Pressure transducers monitored by the central processing unit are used both to control gas pressure and to measure experimental results.

The capacity of the sample tip and manifold may be different for different systems. However, in the device used for the test, the cap capacity included between the sample cap C and the corresponding closing cap valve V is 7 cat', while the valve +4.
15, 23. From 28 and Vl, ■8 is all closed,
The manifold volume contained in the manifold was 19 cm'.

During operation, in the first stage, valves 14 and 15 remain closed while valve 2
3.28 and 29 are open, and both valves V1 and V8 associated with the tip containing the sample are opened.

Vacuum is applied to the manifold and sample in this manner for approximately 90 minutes. The vacuum is then closed and valves 15 and 17 are opened to expose the sample in the sample cup to constant methane gas pressure for at least 90 minutes. At that point, the valve 15 is closed, and all of the valves V1 and 8 are closed. Next, the manifold is exhausted and closed, and one of the valves (1) and (8) is opened. Because of this, pressure is released into the manifold. When the tap valve V opens, the pressure transducer measures the pressure in the manifold in very short time intervals, for example 0.2 seconds. These pressure readings are recorded and represent the variation in pressure over time from opening of the sample valve, thereby providing a ΔP index.

EXPERIMENTAL EXAMPLE To demonstrate the operability of the apparatus according to the present invention, samples of bituminous coal from British Columbia with a particle size of 20 to 6 Q Tyler mesh were tested. Approximately L kg of the sample was oxidized for 4 weeks at a temperature of 100° C. with an oxygen flow rate of 45 zC/min, and the remainder of the sample was stored in its original state. The original unoxidized coal sample and the oxidized coal sample were then heated for 39R1 min, ΔP, respectively.
A test of 2% of failure decisions was performed using the apparatus of the present invention. The results are shown in FIG. 5, and it can be seen that the non-oxidized sample has a much higher ΔP index than the oxidized sample.

Therefore, the present invention has the configuration as described in detail in the above embodiments, and can achieve the intended purpose.

[Brief explanation of drawings]

The drawings illustrate the configuration of the present invention; FIG. 1 is an overall flow sheet of the system according to the present invention, FIG. 2 is a sectional view of the sample tip assembly, and FIG. 3 is a diagram of the tip valve. FIG. 4 is a side view of the cooling device, and FIG. 4 is a cross-sectional view of FIG.
FIG. 5 is a graph showing test results for oxidized coal and non-oxidized coal. 10... Main unit, 11... Cylindrical manifold, CI
-CB...Sample tip, Vl-V8...Solenoid valve, 14,15. IL-・Solenoid valve, 16・Proportional control valve, 18...Ultra high purity gas filter, I9・
Flash arrester, 20...pressure regulator, 21...
...Methane gas source, 22... Branch line, 23, 28.29
...Solenoid valve, 30..Manual blow-off valve, 32.
・Two-stage vacuum pump, 40... Cylindrical part, 41... Threaded part, /12... Nut, 43... O-ring, 45...
・・Disc filter, ・160-link, 50...
Water-cooled aluminum radiator, 53/main body, 54.55
...Aperture. Patent applicant: Canadian Patent & Development Limited Agent: Patent attorney: Aoyama Aoyama and two others Engraving of the drawings (no changes to the content) Figure 2 Figure 4

Claims (1)

Claims: 1) An apparatus for measuring the ΔP index in coal, comprising: (a) a plurality of closed coal sample cups; and (b) a gas connected to each of the sample cups via a separate solenoid valve. a manifold flow path, the manifold being connectable via solenoid valve means to a source of methane gas, and also connectable via solenoid valve means to a vacuum source; (c) further connecting said manifold to a source of vacuum; a pressure transducer connected and arranged to measure the absolute gas pressure in the manifold; and (d) processing means for actuating the valve, the processing means comprising: (ii) introducing methane gas into the manifold and saturating the one or more coal sample cups therewith; (iii) evacuating the one or more sample cups; while closing the cup valve and evacuating the manifold, and (iv) operating each valve in sequence so as to individually selectively open each sample cup valve, the processing means A measuring device characterized in that the pressure inside the manifold is measured and recorded at short intervals so as to indicate the accompanying pressure increase in the manifold, and the ΔP index of a coal sample is obtained. 2) A measuring device according to claim 1, comprising:
A measuring device comprising a pressure control means for controlling the methane gas pressure in the manifold to a predetermined pressure. 3) A measuring device according to claim 1, comprising:
A measuring device characterized by a sample cup valve attached to a water-cooled aluminum cooling radiator. 4) A measuring device according to claim 1, comprising:
A measuring device characterized in that a processing means is constituted by a microcomputer.